1. Field of the Invention
The present invention relates to a printer which can print characters and other data in accordance with input signals and, more particularly, to a printer which is suitable for use in measuring or controlling purposes and capable of ensuring high quality of recording by printing even in an atmosphere which is rich in contaminants such as water, oil, dust and so forth, while facilitating the management of the record.
2. Description of the Prior Art
In recent years, a rapid progress has been made in the fields of electrical measurement and control. The measurement or control by electrical means usually requires, for the purpose of recording the results of measurement or the procedure of the control operation, a printer which is capable of printing characters or other data on a sheet of recording paper in accordance with input signals. The use of such a printer contributes to improvement in the efficiency of the measuring or control operation, and enables such an operation to be conducted in a rational way.
For instance, Japanese Patent Publication No. 33574/1984 of the same applicant discloses a measuring system which incorporates a printer as a recording means together with a digital display device, so that the measured data is recorded by the printer. This conveniently eliminates the necessity of manually transcribing the displayed data to, for example, a data sheet, so that the efficiency of the work is remarkably improved.
This known printer, however, suffers from the following disadvantages. Namely, this type of printer usually does not have any means for suitably guiding or directing the data sheet coming out of the printer after the recording, nor means for positively packing or stacking the same. It is, therefore, often experienced that the data sheet after the recording, which usually has an upward curving or buckling tendency, is turned upside down to hinder the visual check of the recorded data.
In some cases, a long data sheet after recording, which has been continuously discharged from the printer, is folded and tangled in a random manner or falls onto the floor, with the result that the data sheet is contaminated or damaged through contact with other devices. In addition, the user often encounters a problem in moving the printer, owing to difficulty in handling of the long data sheet after recording.
In order to overcome this problem, it has been proposed to cut the data sheet coming out of the printer in a suitable length. This countermeasure, however, suffers from various problems. For instance, the sequence of successive cut sheets of record, which carry a group of voluminous data, may be disordered or one of more cut sheets may be lost, so that the operator is obliged to take a labor for putting the sheets in order or finding the lost sheets. It is of course possible to put the sheets in order and to stack them by manual labor. This, however, requires a suspension of the measuring work, thus impairing the advantage offered by the printer. In addition, the manual work tends to cause the data sheets to be contaminated by water or oil which may have attached to the operator's hand.
In general, a printer has a cover which is provided with slits or similar openings such as that for discharging the data sheet after the recording. Thus, the interior of the printer tends to be damaged or contaminated by water, oil or dust which may be introduced into the printer through these openings, particularly in the case where the printer is used in an environment rich in such contaminants. In such a case, needless to say, there is a risk that the data sheet after the recording, which has been discharged out of the printer, is contaminated or broken. This has given a rise to a demand for a protective measure for protecting the interior of the printer and the data sheet before and after the printing, against any contaminant such as water, oil or dust which may exist around the printer.